Effects Of High-Intensity Interval Training On Cardiometabolic Risk Factors And Motivation To Exercise In Women With Abdominal Obesity

Abstract

There has been recent interest in high-intensity interval training (HIIT) as an alternative to moderate-intensity continuous training (MICT) to reduce body composition, adiposity and cardiometabolic risk factors in obese patients. Despite the promising evidence supporting HIIT in this population, there is limited research targeting women with abdominal obesity. PURPOSE: The objective of this study was to compare the effects of MICT and energy-matched HIIT on cardiometabolic risk factors in women characterized by abdominal obesity. METHODS: Twenty abdominally obese women (age range, 28-56 years) were submitted to 12 weeks of intervention and were randomly allocated into 2 groups: MICT (n=10) and HIIT (n=10). The MICT group performed a 38 to 62-minute continuous exercise at 70 % of the maximal heart rate. The HIIT group training performed 3 to 6 sets of 4-minute bouts at a running velocity corresponding to 90 % maximal heart rate, interspersed by a 4-min active recovery period at 50 % maximal heart rate. Anthropometric parameters, maximal oxygen uptake (VO2max) and cardiometabolic risk variables were measured at the beginning and after 12 weeks. Self-determined motivation toward physical activity was also evaluated with a validated questionnaire. RESULTS: MICT intervention led to significant improvements in VO2max (29.9 to 32.7 ml O2*kg-1*min-1, p=0.005), with no change in HIIT group. However, at the beginning of the study, VO2max was significantly lower in the MICT group when compared to the HIIT group (p=0.04). During the intervention, no significant difference was found in cardiometabolic risk factors in the MICT group. However, HIIT resulted in statistically significant reduction in triglycerides levels (1.91 to 1.58 mmol/l, p=0,046) even though waist circumference was significantly increased (98.0 to 100.7 cm, p=0.038) after the 12-week intervention program. In addition, the HIIT group increased self-determined motivation toward physical activity in a greater magnitude when compared with the MICT group (p=0.016). CONCLUSION: HIIT appears to provide greater benefits to MICT for improving triglyceride levels. In addition, as HIIT is associated with a greater improvement in self-determined motivation toward physical activity, HIIT could be associated with promising long-term adherence to exercise.